3 Mosquito-Borne Diseases and their Reach into Iowa

West Nile Virus

The West Nile virus can be transmitted to both humans and animals through its vector: the mosquito. The majority of people infected by the West Nile virus experience no to mild symptoms. Symptoms typically include fever, headache, and body aches. Less than 1% of those infected will develop serious neurological illness, such as encephalitis and meningitis. If gone untreated these complications can be fatal.

The first case of West Nile Virus in Iowa was discovered in September of 2001. Since then there have been cases reported annually.

La Crosse Encephalitis

La Crosse Encephalitis is transmitted to humans by the Aedes triseriatus mosquito. This particular breed of mosquito is commonly active during the day and can be found in or near wooded areas. Most of the time infection is undetected. When symptoms do occur they include fever, headache, nausea, vomiting, and tiredness. In rare instances the disease will progress to cause neurological illness such as encephalitis. This may lead to seizures, coma, or paralysis. These neurological conditions may result in long-term disability or death.

Cases of La Crosse Encephalitis do occur in Iowa, but they are reported infrequently.

Saint Louis Encephalitis

Saint Louis Encephalitis is spread to humans by the bite of an infected mosquito. Symptoms, in most cases, are uncommon but can include fever, headache, nausea, vomiting, and tiredness. Older adults are more likely to experience severe neurological illness that may result in long-term disability or death.

Saint Louis Encephalitis is more common in the Eastern and Central parts of the United States, but cases do occur in Iowa.